1. Field of the Invention
This invention relates to methods of and apparatus for mounting articles to a carrier member. More particularly, another aspect of the invention relates to handling small articles, such as beam-lead integrated circuit chips, prior to bonding the chips to the substrates. Adhesive dots are applied around the periphery of apertures in a tape. The size and shape of each of the apertures are chosen to form pockets for the chips. The chips then are loaded from an expanded array into the pockets of the tape, suspended by at least some of the beams attached by the adhesive dots to the periphery of these pockets. Thereafter, the tape is run onto a spool to store the loaded chips for future bonding of the chips onto substrates. The bonding is accomplished during a transfer of the chips directly from the tape to the substrate. Bonds are preferably formed by a thermocompression process, wherein the tape serves as a compliant member between the chips and a thermode applying the thermocompressive energy.
2. Description of the Prior Art
U.S. Pat. Nos. 3,785,903 and 3,871,936 to J. A. Boyer, D. P. Ludwig and F. Zwickel issued Jan. 15, 1974, disclose prior art apparatus and methods, respectively, which relate to the subject matter of the present invention. The Boyer et al. patents also make reference to other prior art patents which relate to beam-lead semiconductor devices, compliant bonding and other related subject matter.
The Boyer et al. patents particularly disclose apparatus and methods for loading beam-lead chips into preselected locations of a compliant tape. The compliant tape can then be supplied to a bonder, the beam-lead chips being already loaded in the tape and aligned for sequential bonding to respective substrates.
A load station of the apparatus disclosed by Boyer et al. includes facilities for first indexing one of the preselected locations into rough alignment with the load station. Thereafter, other facilities precisely align such locations. The disclosed apparatus further includes facilities for applying a plurality of dots of adhesive to the tape. The adhesive dots are applied prior to loading the chips to the tape. The dots form a pattern about the periphery of each of the locations on the tape. The pattern is intended to be coincident with selected leads of the chips to be loaded. Successive locations of the tape are first indexed into at least rough alignment with the applying facilities. Indexing the tape shifts other locations away from the applying facilities and toward the load station. After the tape is indexed, roughly aligned locations are precisely aligned to both the applying facilities and to the loading station so that the applying facilities can be simultaneously activated with the facilities for loading one of the chips.
It is desirable to integrate and simplify the alignment of preselected locations or sites on a length of tape with respect to a chip load station.